GMC 2008 Acadia - Manual (Page 112)

Automatic Transmission Operation
Your vehicle has an electronic shift position indicator
within the instrument panel cluster.
When using the Electronic Range Select Mode a
number will display next to the L, indicating the current
gear that has been selected.
See Electronic Range Select mode in this section for
more information.
Your automatic transmission has a shift lever located on
the console between the seats.
PARK (P): This position locks your front wheels. It is
the best position to use when you start your engine
because your vehicle cannot move easily.
{ CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Do not leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move
suddenly. You or others could be injured. To
be sure your vehicle will not move, even when
you are on fairly level ground, always set your
parking brake and move the shift lever to
PARK (P). See Shifting Into PARK (P) on
page 2-36. If you are pulling a trailer, see
Towing a Trailer on page 4-30.
2-30